[Bug]: Possibly broken user agent client hint

[webdevmario]

Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Electron Version

13.1.7

What operating system are you using?

Windows

Operating System Version

Windows 10 version 20H2

What arch are you using?

x64

Last Known Working Electron version

12.0.15

Expected Behavior

Checking navigator.userAgentData in Chrome 91 returns an array of brands appropriately. Electron 13/14 do not return anything.

This appears to then become a problem for my situation. I am posting a form with hidden variables to a third-party vendor I work with. This form post ultimately loads an iframe.

Expected: As it does in Chrome 91, load the iframe from this third-party vendor.

Actual Behavior

A header of "sec-ch-ua" is included in the request to the third-party vendor and it is blank. They are rejecting the post because of an invalid header. I suspect this is because Chrome 13/14 does not make this hint data made available correctly.

I tried loading various sites in Chrome 91 that do load brand names in Electron 13/14 and they are empty if you review navigator.userAgentData.

Testcase Gist URL

No response

Additional Information

No response

[quanglam2807]

I confirmed this bug.

navigator.userAgentData and navigator.userAgentData.getHighEntropyValues return empty values.

[Swastyy]

@webdevmario Hi, is this issue fixed? If not, I want to work on this.

[nornagon]

I have a branch which starts on this, but it interferes with some other UA overriding stuff, so it's not quite straightforward. https://github.com/electron/electron/compare/navigator-useragentdata is my WIP, for reference.

[phryneas]

We had problems with this as the empty sec-ch-ua header triggered a WAF.
Not really a solution, but a mitigation strategy until this gets fixed:

app.commandLine.appendSwitch('disable-features', 'UserAgentClientHint');

[jarek-foksa]

I can reproduce this bug with Electron 19.0.3 running on macOS 12.4. This should have higher priority as Chrome Dev Tools are now instructing developers to migrate away from navigator.userAgent to navigator.userAgentData.

[nornagon]

Cleaned up and finished off my branch, #34481 should fix this.

[Shamar]

Hi, looks like client hints are still broken in electron 25.4.0: by setting app.userAgentFallback, the User-Agent header is correctly set in requests, but clients hints such as SEC-CH-UA, SEC-CH-UA-MOBILE and SEC-CH-UA-PLATFORM are not (despite easy to reconstruct from the userAgentFallback.

Also the navigator.userAgentData completely ignores the userAgentFallback, while the navigator.userAgent seems correctly set.